Women’s private and workplace pensions are also often less generous than men’s because they tend to earn less and take time away from their jobs to have children.

Research by the Department for Work & Pensions shows women are more likely than men to retire without any savings. More than 70 per cent of women said they found pensions complex and 28 per cent said they were scary.

Tomorrow’s white paper will also outline a radical simplification of the state pension. At the moment, many recipients claim three parts: a basic element, the second state pension and the pension credit - a top-up payment for the poorest old people which is claimed by only 40 per cent of those who are entitled to it.

Ministers hope the new single-tier system will be simpler and encourage more people to save for their old age.

Critics argue that extensive means testing in the current system discourages those nearing retirement from putting money away. The current system also requires a large bureaucracy to process the different elements of the state pension.

However, the system could also see six million workers in final-salary pensions schemes pay higher National Insurance contributions. The vast majority of these people work in the public sector.